Spontaneous. Unpredictable. Avant-garde.Just some words to describe a lesson with a teaching maverick.Every team has one, or at least they used to. To teaching, what Eric Cantona was to Manchester United. A flair player.My favourite maverick at school was Mr “JJ” Johnston (pictured in 2001). A tall, bearded intellectual who always carried a rather regal briefcase and whose lessons were tangents within themselves. Oh, but did we learn, and did we flourish. Debates, conjecture and educational chivalry all took place within stark temporary classrooms with little heating.